Water energy: a wealth to exploit in the respect of environment

Men have developed technologies, sometimes surprising, allowing to capture a small part of the kinetic energy carried by rivers, streams or waves. Classical hydropower plants, from big dams to micro-hydroelectric plants, are well-known technologies, but beside these, the most ingenious systems can be found on the marine side: submarine turbines, 'sea snake' wave energy converters, offshore wind turbines or production of biomass fuels from algae cultivation. These new energy sources are going to occupy an increasing place in tomorrow's energy landscape but, like for any human intervention in the natural ecosystems, care must be taken to exploit the energy of the precious water resource in the respect of the environment. (J.S.)